A cordless telephone is a telephone that communicates via radio waves with a base station connected to a fixed telephone line. The base station is located in the subscriber's premises and attaches to the telephone line in the same way a regular wired telephone receiver does. When a person uses a cordless telephone, he or she can take the handset and go anywhere in his or her house without being constrained by a wire. Cordless telephones have been manufactured since the 1980s.
Digital Enhanced Cordless Telecommunications (DECT) is a standard specification for cordless telephone receivers. DECT fully specifies the means for a cordless handset to access a fixed network via radio. It specifies, signal frequencies to be used as well as protocols for communication between handsets and base station devices. The first DECT standard was published in 1991.
The rapid development of the Internet throughout the 1990s saw the development of another standard. The Cordless Advanced Technology—Internet and quality (CAT-iq) standard was specified to bring together broadband Internet and telephony. CAT-iq is intended to coexist with DECT.
CAT-iq specifies the means for delivery of additional services on DECT-compliant handsets. CAT-iq handsets can make both calls over the telephone network (PSTN) and calls over the Internet (e.g., VoIP, etc.). Furthermore, CAT-iq handsets have the ability to receive data services, such as Internet radio, for example. CAT-iq is an enhancement to the DECT standard because it enables the delivery of advanced services that are not available in DECT.
DECT and CAT-iq are designed to promote interoperability. Devices that implement the DECT/CAT-iq standards are expected to be compatible with one another regardless of their implementation details. From a practical standpoint that means that a user can buy a handset from one manufacturer and expect it to interact successfully with any other manufacturer's base station device.